US 2016/0046761 relates to controlled biodegradable smart responsive scaffold (SRS) materials that enhance attachment and viability of cells, i.e. actively guiding their expansion, proliferation and in some cases differentiation, while increasing their biomechanical functionality. The same is an important key issue for tissue regeneration. Chemically build-in functionality in these biodegradable SRS materials is achieved by varying structural functionalization with biocompatible liquid crystal motifs and general polymer composition allowing for regulation and/or alteration of tensile strength, surface ordering, bio-adhesion and biodegradability, bulk liquid crystal phase behavior, porosity, and cell response to external stimuli. Liquid crystal modification of such polymeric scaffolds is an ideal tool to induce macroscopic ordering events through external stimuli (in some cases without external stimuli).
An article by SHARMA, A. et al, titled “Biocompatible, Biodegradable and Porous Liquid Crystal Elastomer Scaffolds for Spatial Cell Cultures”, Macromol. Biosci. 2015, pp. 200-214, Vol. 15 relates to a report on the modular synthesis and characterization of biodegradable, controlled porous, liquid crystal elastomers (LCE) and their use as three-dimensional cell culture scaffolds. The elastomers were prepared by cross-linking of star block-co-polymers with pendant cholesterol units resulting in the formation of smectic-A LCEs as determined by polarized optical microscopy, and X-ray diffraction. Differential scanning calorimetry (DSC) helped determined glass and phase transition temperatures. Scanning electron microscopy (SEM) revealed the porosity of the as-prepared biocompatible LCEs, making them suitable as 3D cell culture scaffolds. Biodegradability studies in physiological buffers at varying pH show that these scaffolds are intact for about 11 weeks after which degradation sets in at an exponential rate. Initial results from cell culture studies indicate that these smectic LCEs are compatible with growth, survival, and expansion of cultured neuroblastomas and myoblasts when grown on the LCEs for extended time periods (about a month). These preliminary cell studies focused on characterizing the elastomer-based scaffolds' biocompatibility and the successful 3D incorporation as well as growth of cells in 60 to 150-mm thick elastomer sheets.
An article by GAO, Y. et al., titled “Biocompatible 3D Liquid Crystal Elastomer Cell Scaffolds and Foams with Primary and Secondary Porous Architecture, ACS Macro Letters, 2016, pp. 4-9, Vol. 5 relates to 3D biodegradable and highly regular foam-like cell scaffolds based on biocompatible side-chain liquid crystal elastomers have been prepared. Scaffolds with a primary porosity characterized by spatially interlaced, interconnected microchannels or an additional secondary porosity featuring interconnected microchannel networks define the novel elastomeric scaffolds. The macroscale morphology of the dual porosity 3D scaffold resembles vascular networks observed in tissue. 3D elastomer foams show four times higher cell proliferation capability compared to conventional porous templated films and within the channels guide spontaneous cell alignment enabling the possibility of tissue construct fabrication toward more clinically complex environments.
Synthesis of Biocompatible Liquid Crystal Elastomer Foams as Cell Scaffolds for 3D Spatial Cell Cultures. J. Vis. Exp. (122), e55452, doi:10.3791/55452 (2017).
SHARMA, A. et al, titled “Effects of Structural Variations on the Cellular Response and Mechanical Properties of Biocompatible, Biodegradable, and Porous Smectic Liquid Crystal Elastomers”, Macromol. Biosci. 2017, article number 1600278, Vol. 17.